Fifty U.S. attorneys general on Monday announced an investigation into potential antitrust violations by Google, marking the latest attempt to regulate the tech giant.

Texas Attorney General Ken Paxton (R) announced the probe at a press conference on the steps of the U.S. Supreme Court, saying Google “dominates all aspects of advertising on the internet and searching on the internet.”

“They dominate the buyer side, the sellers’ side, and even the video side with YouTube,” Paxton said, according to Gizmodo.

Google’s parent company, Alphabet, has a market value of over $820 billion and owns dozens of online subsidiaries. 

Attorneys general for the District of Columbia, Puerto Rico and all U.S. states except California and Alabama are joining the bipartisan probe into whether Google has engaged in anticompetitive behavior.

“When there is no longer a free market or competition, this increases prices, even when something is marketed as free, and harms consumers,” Florida Attorney General Ashley Moody (R) said of the investigation, according to CNBC. “Is something really free if we are increasingly giving over our privacy information? Is something really free if online ad prices go up based on one company’s control.”

Kent Walker, Google’s chief legal officer, published a blog post on Friday responding to the upcoming probe.

“We have answered many questions on these issues over many years, in the United States as well as overseas, across many aspects of our business, so this is not new for us,” Walker wrote. “The DOJ has asked us to provide information about these past investigations, and we expect state attorneys general will ask similar questions. We have always worked constructively with regulators and we will continue to do so.”

Monday’s announcement comes just days after New York Attorney General Letitia James (D) launched a multi-state investigation into possible antitrust violations by Facebook. 

That investigation is examining “Facebook’s dominance in the industry and the potential anti-competitive conduct stemming from that dominance,” James’ office said. Attorneys general for Colorado, Florida, Iowa, Nebraska, North Carolina, Ohio, Tennessee and Washington, D.C., have joined the probe.

Both Google and Facebook are also facing antitrust scrutiny on the federal level. Facebook in July agreed to pay a record $5 billion fine to the Federal Trade Commission over allegations that it committed privacy violations following the Cambridge Analytica scandal.

Meanwhile, The Wall Street Journal reported in June that the Justice Department was gearing up to conduct its own antitrust investigation into Google. The FTC, which oversees antitrust violations alongside the DOJ, previously investigated Google but closed the probe in 2013 without taking action.

Google last week also agreed to pay the FTC $170 million to settle allegations that YouTube, one of the company’s subsidiaries, unlawfully collected children’s personal data without their parents’ consent.